1. Field of the Invention
The present invention relates generally to brake systems, and more particularly to an in-line secondary master cylinder which operates independently of a primary input device to ensure independent secondary subsystem operation and brake system integrity during periods of primary brake circuit instability or failure.
2. Description of the Prior Art
It is desirable to have a hydromechanically regulated vehicle brake system which accommodates multiple, e.g. hand and foot, manual input forces such that deterioration or failure of any one of the subsystems (such as hand and foot) will not disable the other. Hydromechanical brake systems are commonly utilized on recreational vehicles such as all terrain vehicles (ATV) as well as motorcycles, for example. Hydraulic brakes often are used as foot brakes on automobiles. Automotive brake systems use liquid pressure to force brake pads against rotors on selected wheels and thus stop the wheels from turning. The liquid is contained in actuation devices called brake calipers. These calipers are connected by special tubing to a pressure and flow generating device called a master cylinder, which is connected to the hand or foot operated force input lever. When the driver actuates the lever, the lever pushes a piston in the master cylinder. This piston forces fluid through the tubes and against the pistons in the calipers. These pistons force the brake pads against the brake rotors or drums, which slows or stops the wheel from turning.
Many of the basic principles of automotive hydraulic brake operation are common to recreational vehicle brake systems which employ hydraulic braking. Recreational vehicles also employ more than a single independent braking system. Examples include a hand operated brake as well as a foot operated brake. It is desirable to have a system for such vehicles which will allow for integrated operation of all independent braking system calipers from a selected primary system input device which may be hand or foot operated, as well as a secondary mode of operation from a second input device, e.g. secondary master cylinder.